Farm implements and toolbars designed to carry tillage tools are being manufactured in larger and wider sizes to improve the farmer's productivity. Toolbars designed to carry tillage tools are typically comprised of a center section that is positioned directly behind a tractor and normally include transversely extending outer sections pivotally connected at their respective inner ends to the center section. In some instances, there are as many as two additional outer sections or frames pivotally connected together and coupled with each outer end of the center section. Today a single tractor often pulls several transversely aligned implement sections which may extend in width as much as sixty feet from end to end.
One of the major problems encountered with these extremely wide implements occurs when the implement width must be reduced to permit transport over roads and through fence gates.
One method commonly used to move an extremely wide implement is to detach the implement from the tractor, move the tractor to one end of the implement, re-attach it and then transport the implement lengthwise with respect to its transverse dimension. The disadvantage with this type of implement is that there must be provided duplicate hitching structure. Further, the implement length to be transported must equal the working implement width and consequently, significant control and turning problems are encountered as it is moved along roads or through gates.
Another method commonly provided utilizes hydraulic cylinders between the center and outer sections to swingably raise the outer section vertically above the outer end of the center section. While this has proven somewhat successful for three section implements, folding mechanisms for implements having more than three sections become very expensive to build and maintain. It has also been common to rotate the implement sections forwardly about vertical pivots on opposite ends of the center section to positions alongside the tractor. Since the implements or tools mounted on the section or toolbar normally extend rearwardly, the overall width of the forwardly folded implement and tractor will equal the width of the tractor plus the depth of both implement sections and their tools. Often this width is too great for the transport problems mentioned. Further, no provision is made with this type of design for implements having more than three sections.
In view of the above-mentioned problems, it would be desirable to swing the outer sections rearwardly of the center sections. One of the major difficulties not overcome with respect to swinging the outer sections rearwardly occurs because the tools mounted on these sections normally project rearwardly. Consequently, when the outer sections are swung rearwardly, interference between the tools on the center section and the tools on the outer section occurs. Thus, there has not been a great deal of success with this method.